In a known filter holder of this type, used in an espresso machine, bringing hot water to the ground coffee contained in the filter at a pressure of 10 to 15 bars, the production of foam in the infusion leaving the filter is achieved by passing the infusion through an over-pressure valve installed on the upper face of the body, and making the mouth of the infusion output strainer communicate with the distribution funnel. However, such an over-pressure valve is an expensive component and its installation on the upper surface of the body is difficult to achieve.